Hyperacusis is defined as an abnormal intolerance, heightened sense of volume and physical discomfort towards certain sounds, which other people can tolerate comfortably. Sounds that are typically difficult to tolerate are loud/impact/sustained sounds, particularly if they are unexpected or in close proximity.

There is a strong association between tinnitus and hyperacusis. Recent prevalence data documents the presence of hyperacusis in 46% (Westcott et al 2013) and 55% (Schecklmann et al 2014) of patients sufficiently affected by their tinnitus to attend a tinnitus clinic.